Publis ed: For two-letter codes and other abbreviations, refer to the "Guid- - v / ithout intemational search report and to be republished ance Notes on Codes and Abbreviations" appearing at the begin- ning receipi of that report no of each regular issue of the PCTGazette.
PROCESS AND FOUNDRY PRODUCT FIELD OF THE INVENTION. The present invention relates generally to foundry processes and casting alloys. More particularly, the present invention relates to an aluminum alloy for use with a high pressure casting technique. BACKGROUND OF THE INVENTION. It is common in the foundry industry to produce products that require high strength, wear resistance, hardness, and / or ductility, using aluminum alloys, such as secondary 356 and A356.2 together with mold casting processes. permanent gravity (GPM for its acronym in English). The GPM casting technique involves heating a metal and pouring the molten metal into permanent metal molds while allowing gravity to act to fill the mold cavity with molten metal. The main difference between casting with permanent mold and conventional die casting, which comprises using high pressures and high casting speeds, is that the molten metal is simply cast without using any external mechanical forces, instead of being injected into a mold, as is done with conventional die casting. Typically, products made with the GPM casting technique tend to have greater strength and are less porous than products made with conventional die casting. The mechanical properties of a product do not only depend on the casting technique used, it also depends on the casting alloy used. Aluminum alloys are commonly used in the foundry industry because they can be adapted to many of the most commonly used casting methods, can be quickly molded into molds or presses and have a high corrosion resistance. Aluminum alloys as a casting material also provide good fluidity, that is, the majority of the alloy flows easily. This is particularly important because if the metal, when in the melted state, does not flow to an insufficient cup to fill the cavity of the die or mold 2 before the molten metal solidifies, then there will be difficulties in filling, for example, Narrow sections of the mold or die. Additionally, aluminum alloys have relatively low melting points. Accordingly, the amount of heat required to melt aluminum alloys is less than the heat required for some other metals, and therefore, the cost of producing aluminum alloys is lower. In addition, there is a smaller amount of heat to transfer from the molten aluminum alloy to the mold. As a result, the cycle time required to melt an aluminum alloy is reduced. Additionally, the life of the mold is increased by using aluminum alloys because the molds are subject to less heat stress. In particular, the secondary aluminum 356 and A356.2 alloys are commonly used with the GPM casting technique to manufacture products that require high strength, wear resistance, hardness and / or ductility. The chemistries of the aluminum alloys 356 secondary and A356.2 are the following: 357 A356.2
Percentage Percentage Element Weight weight element Silicone 6.5-7.5 Silicone 6.5 - 7.5 Iron 0.12 Max Iron 0.6 max Manganese 0.05 Max Manganese 0.35 Max Magnesium 0.30 - 0.45 Magnesium 0.20 - 0.45 Zinc 0.50 Max Zinc 0.35 Max 0.25: Max Titanium 0.20 Max Titanium
Strontium 0.03 max Strontium 0.03 max
Copper 0.10 max Copper 0.25 max Other 0.15 max Other 0.15 max Aluminum Balance Aluminum Balance 3
However, there are specific problems associated with aluminum alloys 356 secondary and A356 when used as cast metal. For example, the melting temperature of the secondary alloy 356 and A356.2 melting is approximately 1, 320 degrees Fahrenheit (715.5 degrees Celsius). When castings are produced with alloys with casting temperatures of 1, 320 degrees Fahrenheit, solder occurs. Welding refers to the adhesion of aluminum to the cavity of a mold or die, which, after a certain period of time, causes the mold or die to no longer be used. It is common in the automotive industry to produce master cylinders and brake-proof brake components (ABS) from secondary 356 aluminum alloys and A356.2 using GPM. Brake systems are used to slow down a vehicle and brake it completely, or to keep the vehicle stationary if the vehicle is parked. The master cylinder is one of the control devices for vehicle brake systems, such as passenger cars and light commercial vehicles, which is used to apply pressure to the wheel cylinders. The ABS components are control devices that are part of the brake system, which prevent the vehicle's wheel from locking during braking, controlling the pressure applied to the wheel cylinders to maintain the stability of the vehicle. In view of the purposes for which master cylinders and ABS components serve, it is required that they have high mechanical properties in areas such as strength, wear resistance and hardness. In addition, ABS components are required to be ductile, that is, they have the ability to withstand permanent deformation before failure. Typically, after casting master cylinders and / or ABS components, they are heat treated to provide additional strength and hardness, and are anodized to provide additional resistance to corrosion. The products are heat treated to provide the minimum property requirements for the required components as shown below: Minimum properties for master cylinders: 4 Resistance to yield point = ~ 23 ksi Strength to tension = ~ 35 ksi Percentage of stretch = ~ 1% Hardness = ~ 80 BHN
Minimum properties for ABS components Resistance to yield point = ~ 25 ksi Resistance to tension = ~ 35 ksi Percent stretch = ~ 3% Hardness = ~ 80 BHN Master cylinders and components for ABS brakes produced by GPM and aluminum alloys 356 Secondary and 356.2 are typically heat treated to ensure that the products meet the minimum property requirements for their respective product. Normally, the master cylinders are heat treated according to a tempered T6. A typical T6 tempering consists of a solution that treats the smelter at 1,000 degrees Fahrenheit (537.7 degrees Celsius) plus or minus 10 degrees Fahrenheit, for ten hours, tempering with water the smelter and artificially aging the smelter at 340 degrees Fahrenheit (171.1 degrees Celsius) plus or minus 10 degrees Fahrenheit for four to five hours. SUMMARY OF THE INVENTION. Accordingly, it is desirable to provide, at least to some extent, a foundry product, which exceeds in terms of mechanical properties and costs, foundry products made with GPM casting techniques using the secondary 356 aluminum alloys or A356. 2. In one aspect it leaves present invention, a product consisting of an aluminum alloy which includes an ADC12 aluminum alloy is provided, wherein the aluminum alloy ADC12 is used to form the product using a high pressure and low speed casting technique. . In another aspect of the present invention, a braking system is provided which includes a braking component, wherein said braking component is made of an aluminum alloy ADC12, and wherein the aluminum alloy ADC12 is used to form the braking component using a casting technique of high pressure and low speed. In still another aspect of the present invention, there is provided a method for manufacturing a component made of an aluminum alloy, which comprises injecting an ADC12 aluminum alloy into a die and applying a high pressure and low casting technique. speed. In another aspect of the present invention, a casting apparatus is provided, which includes means for injecting an ADC12 aluminum alloy into a die, and means for applying a high pressure casting technique. Thus, the most important advantages of the present invention have been described, in a very general way, so that the following detailed description of the invention can be understood more easily, and in order that the present contribution to the art can to be better appreciated, there are, of course, additional features of the present invention which will be described below and which will form the inventive subject matter of the claims. In this regard, before explaining at least one embodiment of the invention in detail, it should be understood that the invention is not limited in its application to the details of construction and arrangement of components described in the following description or illustrated in the drawings. drawings. There may be other modalities and other ways of being carried out. It should also be understood that the paraphraseology and terminology used in the following description, as well as the summary, are intended to describe the invention and should not be taken as limiting. As such, persons skilled in the art will appreciate that the concept on which the present description is based can be used as a basis for the design of other structures, methods and systems to carry out various purposes of the present invention. . Therefore, it is very important that the claims be considered to include said equivalent constructions, as long as they do not depart from the true spirit and scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS. FIG.1 schematically shows parts of the braking system according to the present invention.
6 FIG. 2 schematically shows a casting apparatus according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED MODALITIES OF THE INVENTION. In accordance with the present invention, an ADC12 aluminum alloy is used with a low pressure, high pressure casting technique to produce casting products such as master cylinders and ABS braking components. High-pressure, low-speed casting techniques such as casting by casting involve injecting molten metal into a mold by means of a motorized piston, slowly into the mold / die cavity. When the applied high pressure pushes the molten metal towards the walls of the die / die cavity, the air gaps between the molten metal and the mold / die walls are quickly minimized. Therefore there is a rapid transfer of heat between the metal and the mold / die cavity. Consequently, due to the rapid transfer of heat involved in high pressure casting, the metal cools to a solid state rapidly. As a result of rapid solidification, the grain structure of the foundry is very small, that is, refined. When the ADC12 alloy is used with a high-pressure, low-speed casting technique to melt, for example master cylinders and ABS brake components, the resulting castings exhibit mechanical properties that are higher than the mechanical properties of products manufactured in accordance with GPM casting techniques using aluminum alloys 356 and A356.2. The aluminum alloy ADC12 is composed of the elements listed below, in weight percentage:
Element% by weight Silicon 9.6 to 12.0 Iron 0 to 1.3 Copper 1.5 to 3.5 Manganese 0 to 0.5 7
As shown in the table above, aluminum alloy ADC12 does not require strontium. Strontium is used in an aluminum alloy as a modifying agent to, for example, improve the ductility of the aluminum alloy. Strontium is frequently used in smelting processes that have slow solidification rates, such as GPM smelting and sand casting. The ADC12 alloy, when used with high-pressure, low-speed casting techniques, has a higher solidification rate due to the rapid heat transfer rates that are characteristic of high-pressure casting techniques. Therefore, because the products acquire a high ductility when manufactured according to a high pressure, low speed casting technique, there is no need to use strontium when the ADC12 alloy is used. As a result, the aluminum content increases in the products made of the ADC12 alloy. The cost of aluminum is lower than the cost of strontium. Therefore, the cost of the products made of the ADC12 alloy is lower than the products made with alloys such as the A356.2 and 356 secondary containing strontium. The ADC12 alloy has a silicon content of 9.6 to 12.0 percent of its weight and is higher than the silicone content of aluminum alloys A356.2 and 356 secondary, which comprises 6.5 to 7.5 per cent. cent of your weight. Due to the higher silicon content of the ADC12 alloy, it has a melting temperature of 1,250 degrees Fahrenheit (676.6 degrees Celsius). The melting temperature of secondary aluminum alloys 356 and A356.2 is approximately 1, 320 degrees Fahrenheit (715.5 degrees Celsius). Accordingly, less energy is required to melt the ADC 2 alloy than is required to melt the secondary alloys 356 and 356.2. Therefore, the cost associated with the manufacture of products 8 made of ADC12 is less than the cost associated with the manufacture of products of secondary alloys 356 and A356.2. In addition, the lower temperature Die casting of the ADC12 alloy causes less slag formation in the order of thirty-five percent less than that produced with the secondary 356 aluminum alloy and A356.2. Slag consists of metallic oxide that is formed when the molten metal reacts with air. Slag formation typically occurs before the molten metal is transferred to the die / die cavity. If the slag enters the mold / die cavity and becomes part of the casting, could lead to defective foundries because the casting does not consist exclusively of the desired alloy. Additionally, the lower melting temperature and the higher iron content of the ADC12 alloy, causes fewer occurrences of welding in the order of about fifteen percent less, than that produced with the secondary aluminum alloys 356 and A356.2. Sunbathing refers to the aluminum adhesion of the alloy to the die cavity or die. Over a period of time, welding occurrences reduce the life of the mold. Therefore, using the ADC12 alloy in place of secondary alloys 356 and A356.2 reduces welding and extends the life of the die / die cavity. When a tempered T6, which consists of treating the molten metal with a solution to
932 degrees Fahrenheit (500 degrees Celsius) plus or minus ten degrees Fahrenheit for four hours, tempering with molten metal water and artificially aging the metal at 356 degrees Fahrenheit (180 degrees Celsius) plus or minus ten degrees Fahrenheit for five hours, was applied to alloy ADC12, it surpassed secondary alloys A356.2 and 356 in terms of yield point strength and tensile strength, when the same tempered T6 was applied to secondary alloys A356.2 and 356. The yield point strength, tensile strength and stretch properties resulting from the secondary alloys A356.2, 356 and ADC12 are shown below: g
From the above table, it is clear that the ADC12 alloy has a higher tensile strength than the secondary 356 aluminum alloys and 356.2. The tensile strength corresponds to the maximum load capacity of the metal before the metal breaks. Therefore, the ADC12 alloy has a greater resistance to the application of forces. The higher strength of the ADC12 alloy can be attributed, at least in part, to its refined microstructure, that is, to the smaller grain size that the alloy develops using a high-pressure, low-speed casting technique. Accordingly, the ADC12 alloy is stronger than the secondary 356 aluminum alloys and A356.2 and is therefore more suitable for products that require high strength, for example, components of braking systems, such as master cylinders and components for ABS brakes. FIG. 1 schematically shows a braking system 10 having a master cylinder 20 and an ABS component 30. In addition, when a T6 annealing was applied to the ADC12 alloy, the alloy
ADC12 outperformed the secondary 356 aluminum alloy and A356.2 in terms of wear resistance, which is measured in terms of volume loss of material based on standards established by the American Society of Testing of Materials ASTM G-77, as continues: 10
Therefore, when the ADC12 alloy was subjected to the ASTM G-77 procedures, which involve the measurement of aluminum alloy volume loss by subjecting the aluminum alloy to a rotating cast iron disk for a time As prescribed, the ADC 2 alloy lost less material than the secondary 356 aluminum alloys and A356.2. The greater resistance to wear, that is, less loss of volume of material, can be attributed, at least in part, to the refined microstructure, that is, to a smaller grain size of the foundry that is developed by the use of a casting technique at high pressure and low speed. Typically the products, for example, the master cylinders and the components for ABS brakes are anodized to increase the wear resistance of said products. By using the ADC12 alloy in conjunction with a high-pressure, low-speed casting technique, the amount of anodizing that needs to be applied to the products is reduced or eliminated. Additionally, the ADC12 alloy has a maximum iron content of 1.3 percent of its weight that is greater than the iron content of the secondary aluminum alloy 356 and A356.3, which have a maximum of 0.6 and 0.12 per cent. percent of its weight respectively. When the iron content of an ADC12 alloy is greater than the maximum iron content of a secondary 356 aluminum alloy or A356.2, the product made with the ADC12 alloy will be easier to machine than the product made with the A356 alloy. 2 and / or 356 secondary. The high iron content of the ADC12 alloy facilitates the formation of chips, that is, the formation of platings while the product is machined. Accordingly, it is possible to apply less pressure or pressure to the machine tool when the machine / tool is fed / pushed onto the ADC12 alloy product to effect the initial cut in the ADC12 product., and also when the product of ADC12 is cut, that when the same actions are carried out in products of secondary alloys 356 and A356.2. Therefore, the machine / cutting tool is subjected to less stress and the life of said machine / cutting tool is prolonged with the alloy ADC12. In addition, the cost of ingots of the ADC12 alloy is lower than the cost of ingots of secondary alloys 356 and A356.2 by approximately ten cents per pound. Accordingly, when an ADC12 alloy is used together with a high pressure casting technique for the manufacture of products, for example master cylinders and components for ABS brakes, the products acquire high mechanical properties and are cheaper to produce. FIG.2 schematically shows a casting apparatus 40 utilizing a high pressure casting technique that includes a piston assembly 50 and a mold / die 60. The numerous features and advantages of the present invention will be apparent from the description Detailed description of the invention, and therefore, it is sought that by means of the following claims all the characteristics and advantages of the present invention will be covered, which will fall within the true spirit and scope of the invention. In addition, since numerous modifications and variations can occur to those skilled in the art, it is not desired to limit the invention to exactly the construction and operation illustrated and described, and therefore all possible and equivalent modifications can be considered within the scope of the invention. .